A scheme for sound quality improvement in a user equipment includes a speech enhancement and a speech reinforcement.
The speech enhancement indicates processing of removing noise included in a speech signal. In a circumstance where two users are communicating with each other, background noise present in a user speaking is input to a microphone together with speech and thereby is transferred to a user listening, which degrades the articulation of speech. To solve the above problem, after performing speech enhancement processing for removing noise in a signal input into a microphone of a user equipment of the user speaking, the noise removed signal is transmitted to a user equipment of the user listening. That is, input of speech enhancement processing is a speech signal including noise and input or estimated noise information, and output thereof is a noise removed speech signal.
The speech reinforcement indicates processing of adjusting a volume of speech in order to improve the articulation of speech in an environment where noise exists. The speech enhancement is processing for transmitting only clear speech to the user listening by removing noise in the signal input into the microphone, and the speech reinforcement is processing for increasing the articulation of speech by amplifying a magnitude of a speech signal received from the user speaking. When noise exists in a communication environment, speech of the user speaking output from a speaker is not clearly audible. In this case, a user equipment may increase the articulation of speech by performing speech reinforcement processing for adjusting the volume of speech and then outputting the reinforced speech to the speaker.
In general, the speech enhancement processing is performed at a rear end of the microphone of the user equipment and functions to remove noise in a speech signal to be transmitted to the user listening and then transmit the noise removed speech signal. Also, the speech reinforcement processing is performed at a front end of the speaker of the user equipment and functions to adjust the volume of speech received from the user speaking and output the volume adjusted speech to the speaker.